 /*******************************************************************************
  * Copyright (c) 2004, 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.core.resources;

 import org.eclipse.core.internal.preferences.EclipsePreferences;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.Platform;
 import org.eclipse.core.runtime.preferences.IEclipsePreferences;
 import org.eclipse.core.runtime.preferences.IScopeContext;

 /**
  * Object representing the project scope in the Eclipse preferences
  * hierarchy. Can be used as a context for searching for preference
  * values (in the <code>org.eclipse.core.runtime.IPreferencesService</code>
  * APIs) or for determining the correct preference node to set values in the store.
  * <p>
  * Project preferences are stored on a per project basis in the
  * project's content area as specified by <code>IProject#getLocation</code>.
  * </p><p>
  * The path for preferences defined in the project scope hierarchy
  * is as follows: <code>/project/&lt;projectName&gt;/&lt;qualifier&gt;</code>
  * </p>
  * <p>
  * This class is not intended to be subclassed. This class may be instantiated.
  * </p>
  * @see IProject#getLocation()
  * @since 3.0
  */
 public final class ProjectScope implements IScopeContext {

     /**
      * String constant (value of <code>"project"</code>) used for the
      * scope name for this preference scope.
      */
     public static final String SCOPE = "project"; //$NON-NLS-1$

     private IProject context;

     /**
      * Create and return a new project scope for the given project. The given
      * project must not be <code>null</code>.
      *
      * @param context the project
      * @exception IllegalArgumentException if the project is <code>null</code>
      */
     public ProjectScope(IProject context) {
         super();
         if (context == null)
             throw new IllegalArgumentException ();
         this.context = context;
     }

     /*
      * @see org.eclipse.core.runtime.IScopeContext#getNode(java.lang.String)
      */
     public IEclipsePreferences getNode(String qualifier) {
         if (qualifier == null)
             throw new IllegalArgumentException ();
         return (IEclipsePreferences) Platform.getPreferencesService().getRootNode().node(SCOPE).node(context.getName()).node(qualifier);
     }

     /*
      * @see org.eclipse.core.runtime.preferences.IScopeContext#getLocation()
      */
     public IPath getLocation() {
         IProject project = ((IResource) context).getProject();
         IPath location = project.getLocation();
         return location == null ? null : location.append(EclipsePreferences.DEFAULT_PREFERENCES_DIRNAME);
     }

     /*
      * @see org.eclipse.core.runtime.preferences.IScopeContext#getName()
      */
     public String getName() {
         return SCOPE;
     }

     /* (non-Javadoc)
      * @see java.lang.Object#equals(java.lang.Object)
      */
     public boolean equals(Object obj) {
         if (this == obj)
             return true;
         if (!super.equals(obj))
             return false;
         if (!(obj instanceof ProjectScope))
             return false;
         ProjectScope other = (ProjectScope) obj;
         return context.equals(other.context);
     }

     /* (non-Javadoc)
      * @see java.lang.Object#hashCode()
      */
     public int hashCode() {
         return super.hashCode() + context.getFullPath().hashCode();
     }
 }

